In a transmission region of a transmission-reflection blue phase liquid crystal display device, a backlight source is used as a light source thereof, and thus light passes through the liquid crystal layer only once. While in a reflection region of the transmission-reflection blue phase liquid crystal display device, ambient light is used as a light source thereof, and thus light passes through the liquid crystal layer twice. As a result, a phase delay of the light when passing through the reflection region is twice a phase delay of the light when passing through the transmission region. Consequently, in the transmission region and the reflection region, it is difficult to obtain a same transmission and reflection photoelectric property.
In order to obtain a same phase delay and a photoelectric property curve with a high matching degree in the transmission region and the reflection region, a transmission-reflection blue phase liquid crystal display device with double cell thickness is raised in this field. That is, a thickness of a liquid crystal cell in the transmission region is twice that in the reflection region. With this design, the phase delay of the light when passing through the reflection region is the same as the phase delay of the light when passing through the transmission region, and thus a same transmission and reflection photoelectric property can be obtained in the transmission region and the reflection region. However, since the manufacturing procedure of the transmission-reflection blue phase liquid crystal display panel with double cell thickness is complicated, the inconsistent between the photoelectric property curve and the response time in the transmission region and those in the reflection region would easily be resulted in due to the error of the thickness of the liquid crystal cell generated during the manufacturing procedure.
Moreover, blue phase liquid crystal is facing a problem of over high driving voltage. At present, the problem is generally solved through improving the performance of the blue phase liquid crystal material or optimizing the structure of the electrode used therein. The performance of the blue phase liquid crystal material can be improved mainly through improving the manufacturing procedure of the material, so that the blue phase liquid crystal material with a large Kerr constant can be obtained. However, since the process of synthesizing blue phase liquid crystal material is rather complex, for example, the factors of monomer, photoinitiator, synthesis condition, etc should be taken into consideration when the blue phase liquid crystal of stable polymer is manufactured, the research and development cost thereof is rather high. With respect to the method of optimizing the structure of the electrode, since blue phase liquid crystal display device is mainly driven in an In-Plane Switching (IPS) mode, a penetration depth of a horizontal electric field generated by the parallel electrodes is limited, and a relatively high driving voltage is still needed.
With respect to the aforesaid technical problem, a blue phase liquid crystal display device in which a consistent photoelectric property in the transmission region and the reflection region can be obtained and the driving voltage of the blue phase liquid crystal can be reduced is needed.